Three human lysosomal genes, Alpha-fucosidase, Alpha-mannosidase and arylsulfatase A will be cloned. cDNA's for each will be isolated from a human liver lambda gtll library by screening for antibody reactive plaques. Full-length cDNA's will be isolated and sequenced to establish colinearity with amino acid sequences for each protein. Comparisons with mutants with Alpha-fucosidosis, Alpha-mannosidosis, and metachromatic leukodystrophy will be made after analysis of mRNA and genomic fragments to establish the nucleic acid defects in selected cell lines.